Electropneumatic vigilance control system



I. K. PURI Nov. 11, 1969 ELECTROPNEUMATIC VIGILANCE CONTROL SYSTEM Filed May 10, 1966 40 gii 50 L'Tf E 5 5 lllnpllfllllllllllli m f W1. 6 kww IIIIJ UMU n 0 6 a M m m w M M In en or fade/z Kufrzo zp By W 7% v A Home y United States Patent US. Cl. 246-1 9 Claims ABSTRACT OF THE DISCLOSURE A vigilance control device wherein the driver has to periodically operate a switch to remain alert. If the switch is not operated, then the power supply to the engine is cut off and brakes are applied.

This invention relates to a vigilance control system for use in vehicles such as locomotives and has for its object to produce a construction in which use is made of compressed air and electrical circuit.

According to this invention a vigilance control device comprises a timing chamber connected to a timing cylinder, a springloaded piston within the cylinder operable by air, a set of contacts inside or outside of the said cylinder operable by the piston, one contact at either end of the cylinder when operated through the piston causing the visual and/or audio signals to function, the other set of contacts when operated causing a time delay relay to function, said relay being adapted to cause cutting off the power supply, bringing the engine to idle and penalty brake application to bring the vehicle to a halt after a predetermined interval, an inlet and a discharge opening for the air in the said timing chamber and cylinder, a cancellation switch in the circuit, the arrangement being such that normally the air is introduced into the cylinder and the timing chamber, the piston moves upwards against the force of the spring during a predetermined time interval and causes the contacts at one end of the stroke to operate, to give audio-visual warning signal and simultaneously actuate a time delay relay, and if the cancellation button is operated before the delay relay can act, the air is adapted to be exhausted from the timing chamber and cylinder simultaneously enabling the piston to return by the force of the spring, so that on the return movement of the piston another set of contacts is closed which performs the same function as the upper contacts unless the said cancellation switch is released, to cause admission of the air thereby moving the piston upwardly to repeat the cycle. In the event of failure of the driver to press the cancellation button within the time allowed by the time delay relay when the piston is on top position or to release it when the piston is at the bottom, the time delay relay acts to cause cutting off the fuel/ power and results in penalty brake application.

Other features of the invention will be clear from the drawings accompanying the specification and the description thereof.

Referring to the drawing, 1 is a timing cylinder having a piston 2 with a sealing gasket 3. The piston has a guide rod 4 and is loaded by spring 5. At one end, the cylinder 1 has two openings 6 and 7 respectively for the inlet and exhaust of compressed air. The flow of air into the cylinder through opening 7 is set by a needle valve 8 to suit the required free time cycle for checking the alertness of the driver. A magnet valve 9 opens or shuts the supply of compressed air. The exhaust opening 6, is controlled by magnet valve 10.

For the convenience of manufacture, operation and setting of free time interval, an auxiliary air chamber 62 may be connected to the cylinder 1 as shown through needle valves 63 with opening similar to that of needle valve 8, the chamber 62 having an exhaust passage controlled by magnet valve '64 operating in parallel with magnet valve 10arrangement being such that while initial lift of the piston 2 is quick, the required free time cycle is given by opening of contacts 11 and 12 and closing of contacts 13 and 14 and at the time of exhausting of the air both the timing cylinder and the chamber are exhausted simultaneously.

Outside the cylinder are fitted a set of electrical contact switches 11, 12 and 13, 14 as shown. The set of contacts at each end close simultaneously by the projection on piston rod 4 in its lowest and uppermost positions respectively.

Contact 13 on closing operates audio-visual warning system consisting of horn 15 and light 16. Contact 11 on closing gives the light indication 17. Contacts 12 and 14 operate in parallel and each on closing energizes the actuating coil of a time delay relay 18.

The time delay relay 18 is set to give a predetermined interval before it causes a switch 19 to close, which switch in turn causes circuits for cutting off of power supply and bringing the engines to idle position and also to cause penalty brake application to bring the vehicle to halt.

Electrical circuit The power is supplied from battery 20. In the positive lead is a fuse 21 and a multiple unit operation switch 22 which remains normally closed when the vehicle to which the device is fitted, is working as a single traction unit but is opened to cut off the battery supply when the vehicle is a trailing unit. In the negative lead is an emergency cut out switch 23, and an engine running switch 24. This switch 24 closes due to energization of the coil 25 which is fed by power supply from the power unit (not shown) of the vehicle as soon'as it is started. In the same circuit isa pressure switch 26 which is actuated by the air brake pressure to close either contacts 27 or contacts 28. A lamp 29 always remains ON when the vigilance control unit is operated except when contact 27 is open due to brake application.

In another modification, the cancellation button 40 may be substituted by a foot operated treadle switch, the treadle switch having 3 positions, namely release, neutral and depressed; the release and depressed positions closing the switch contact; the driver being normally called upon to keep the treadle in the neutral position by a light pressure being applied to the said treadle and actuate the release or depressed position only to reset vigilance cycle, the treadle switch thus limiting the time interval for freedom of movement of the driver in the cab to the warning cycle given by the warning time delay relay; an electrical latching type push button switch being incorporated in the treadle switch circuit and thus allowing the driver to perform other functions for the interval of time equivalent to a single vigilance cycle on expiry of which the driver is required to reset the vigilance cycle by operation of treadle switch; failing to do so resulting in penalty brake application after the usual audio/visual warning. The treadle switch is an auxiliary to the cancellation button 40.

Referring to the time delay relay 18 when its contact 19 closes, then solenoid 30 of a relay switch 31 is energized. This causes plunger 32 of the switch to be drawn in thereby moving contact pin 46 and opening contacts 33 which in turn control the supply of traction power to the wheels and at the same time contacts 34 are closed to energize penalty brake application valve 35 with the result that light 36 is switched on and an audio signal 37 operates. There may also be provided a recorder 33 to record incidence of penalty brake application in the same circuit.

' Thus it will be seen that if the driver is not alert and the time delay relay 18 is allowed to function, then power will be cut on and the brakes will be applied, coil 39 of the said switch 31 is intended for restoration of power supply contact 33. This is energized by the closing of a cancellation button 40 in the same circuit. The operation of the cancellation button 40 cannot be effective on solenoid 39 unless throttle switch 41 and reversal handle switch 42 or throttle switch 43 and reversal handle switch 44 which are in parallel with switches 41 and 42 and are meant to serve either side control of a vehicle are also closed. Solenoid 39 on energization draws in plunger 45 to break contacts 34 and make contacts 33 through contact pin 46 mounted on insulated section 47 of the plungers 32 and 45. I

Operation To start with the emergency cut out switch 23 is 'ON and the multiple operation switch 22 is closed, that is, the vehicle (engine) is working as a leading unit, and contact 27 of brake pressure switch 26 is closed due to no air pressure in the engine brake pipe, the engine brakes being released; and contact 33 of the switch 31 is closed so that the supply of current to the vehicle is being effected.

When the engine is started, the coil 25 of engine running switch 24 is energized because it is receiving current from the engine power supply, so that contacts 43 are closed. The battery is now switched on so that the unit becomes operative.

The compressed air passes through magnet valve 9 which is open and is controlled by needle valve 3. The air is admitted to the cylinder through inlet passage 7 and lifts the piston 2 against the tension of loading spring 5. At this stage magnet valves 10 and 64 are in closed position so that the air cannot escape. The piston 2 travels up quickly and after part of the stroke, air starts bleeding into the auxiliary air chamber 62. After a preset interval to give the desired free period (interval of about 2 to minutes between the successive checks on the drivers alertness) the piston moves up to close contacts 13 and 14 which in turn start the audio visual warning system (15 and 16), and energizes the coil of time delay relay 18. At this stage, the driver is required to acknowledge the warning by pressing the cancellation button 46, so that the coils of valves and 64 energizes whereby the compressed air within the cylinder below the piston 2 and in the chamber 62 is exhausted. In case he fails to acknowledge the warning by pressing button 40, then the time delay relay 18 after a predetermined or set interval (e.g. approximately 10 to seconds) closes the contact 19 to energize the solenoid 30, which will draw plunger 32 to open contact 33 and close contact 34. Opening of contact 33 cuts 01f power supply for traction and brings the engine to idling position. At the same time closing of contact 34 causes brake application due to energizing of valve 35 which in turn is indicated by switching on of: light 36 and starting of the audio-warning system 37. It a penalty brake application recorder 38 is provided, then this event of penalty brake application will be recorded.

If, however, the driver has responded to the audiovisual signal given by 15 and 15 by pressing the cancellationbutton 40, then the piston 2 comes down due to exhausting of air through magnet valves 10 and 64 with the result that (a) Audio visual warning signal 15, 16 ceases to function because switch 13 opens and (b) Time delay relay 18 is de-energized as switch 14 is open so that switch 31 does not function.

When the piston reaches the bottom of the cylinder to close contacts 11 and 12, light 17 is switched on and simultaneously the time delay relay 18 is re-energized.

' contact fiil, whereby contact 28 is made thereby energiz- At this stage when light 17 appears, the driver should release button'4),'failing which the time delay relay 18 will close contact 19 after the preset interval to cause penalty brake application in the same manner as described above. On releasing cancellation button 40, magnet valves 10 and 64 are de-energized to close the exhaust passages thereby allowing the air flowing through passage 6 to build up pressure to lift piston 2 instantaneously to restart the timing cycle.

Cancellation butt0n'4t) can be pressed by the driver at any intermediate stage of the upward movement of the piston 2 thereby permitting the driver to reset the equipment. This will enable the driverto obtain a full free cycle perio'dtupWard movement of'the piston) for attending to other jobsih the cab.

'In addition'to thebutton 40, there are provided parallel switches like49 and Stl'which can be operated by certain movements of'the' driver which may signify the alertness of the driver. These switchescould for example be installed' in the throttle or the whistle cock. These switches help inextendi'ng the period between successive operation"ofcancellation button 40, without in any way disturbing the normal periodof check on the alertness of the driver. I

Since the system herein produced provides a constant time cycle, it operates irrespective of whether the vehicle is stationary or in motion, thereby requiring'the presence of the driver in the cab all the time. However, to permit him to get on the cab while the vehicle is stationary, the driver is required to apply his air brake 'which will open contact 27 of the pressure switch 26 and close contact 28, thereby temporarily'suspending the operation of the unit. This is achieved 'by cutting off the compressed air supply to the cylinder 1 through magnet valve 9 which is energized due to closing of contact 28. This will also be indicated by the going off of light 29. The switch 26 functions likewise even when thedriver is controlling his train by brake application on the run, thereby extending the free cycle period. Also, the system stops functioning temporarilywhen a penalty brake application takes place due to closing of contact 19 of the relay 18.

The emergency cut out switch 23 is a double pole throw-over type knife switch housed in a sealed box with a glass face and is provided to disconnect the vigilance control unit completely in case it fails to respond to normal control due to some defect in the system. In its normal position, contact 56 in the negative lead of the battery supply and contact 57 in positive lead of contact 34' of penalty brake application circuit are closed. In case the vigilance control system fails, then emergency switch 23 can be operated after breaking the glass to open contacts 56 and 57, and close contacts 58 and 59; so that on closing of contacts 58, the magnet valve 9 is energized to shut oif supply of air to the cylinder and by closing contacts 59 switch 33 is short circuited to complete engine power circuit even if contactswitch 23 is left openQThis will. bo -indicated by switching off of light v 7 Multiple unit operationswitch 22 is a double pole switch with twosets of contacts 60 and 61. When the vehicle is operating as a single or leading unit, contact 60 in the positive lea'dof battery circuit remains closed thereby keeping the system operative. When the vehicle is'operating as'a trailing unit, then switch 22 is operated along with othercontacts to'open contact 60 and close ing mag'net valve 9 to stopinlet of compressed air into the timing cylinder l. i

V Over'speed control The equipment can-be adapted to provide overspeed control with the-help of known tachographs. This can be achieved by short'circuiting the contact 12 by means of overspeed control switch 51 provided in the tachograph which will set the time delay relay 18 in operation and also operate an audio signal 52.

If the driver does not bring the speed down to the permissible limit within the preset interval of the relay 18, penalty brake application will take place as described earlier.

An automatic train control switch 53 is preferably installed in rail vehicles to specially alert the driver at a safe braking distance, when he is approaching a stop signal. Closing of the switch will short circuit contact 14, energize the time delay relay 18, and start an audiosignal 55 to draw the drivers attention. The driver should at this stage operate push button switch 54 to acknowledge this warning and reopen the said switch 53, failing which penalty brake application will take place after the preset time interval of relay 18. The function of button 54 can also be performed by cancellation button 40 on making appropriate connection.

I claim:

1. A vigilance control device for use in vehicles comprising a timer, a first and a second pair of movable contacts connected to a source of power supply, said two pairs of contacts being in parallel and spaced from each other and adapted to be operated by the said timer, a safety cycle circuit and a vigilance cycle circuit controlled by said first pair of contacts, the closing of the said first pair of contacts by the timer starting the safety cycle and the opening of the said contacts starting the vigilance cycle, a warning cycle circuit controlled by the second pair of contacts on closing representing the end of the said vigilance cycle and beginning of the warning cycle, a time delay relay connected in series in the circuit of the said contacts, the time lag of the said relay when operated by the said first pair of contacts representing the safety cycle and when operated by the said second pair of contacts representing the warning cycle, an indication device in the circuit of one of the contacts in the said first pair of contacts to indicate the start of the safety cycle, the second contact in the said first pair of contacts when closed, simultaneously setting in operation the said time delay relay, an audio/visual signal in the circuit of one contact in the said second pair of contacts to represent when closed, the end of the vigilance cycle and start of the warning cycle, the other contact in the said second pair of contacts being also connected to the said time delay relay to set the said relay in operation, and electrically operated cancellation means adapted to reset the timer during the vigilance cycle or on expiry thereof and within the warning period determined by the time delay relay, and wherein on failure to operate the said cancellation means before the end of the warning period, the said time delay relay is adapted to cut off motive power and apply brakes to the vehicle; the said time delay relay also being adapted to cut oil power supply and apply brakes in the event of the cancellation means not being restored to cause the timer to start the vigilance cycle by opening the said first pair of contacts.

2. A vlgilance control device as claimed in claim 1 comprising a timer consisting of a timing cylinder, a spring loaded piston within the cylinder and operable by a fluid media such as air, a set of contacts operable by the piston rod at extreme ends by the stroke of the piston, an audio/ visual signal in the circuit of one contact at either end of the stroke, a time delay relay in the circuit of the other set of contacts, said relay being adapted to cause cutting off of the power supply to bring the engine to idle and penalty brake application to bring the vehicle to a halt after a predetermined interval, an inlet and a discharge opening for the air in said cylinder, a cancellation switch adapted to control the movement of the piston within the cylinder.

3. A vigilance control device as claimed in claim 2 in which a magnet valve and a needle valve are fitted at the inlet of the cylinder to regulate the flow of air into the cylinder, while another magnet valve is fitted at the exhaust of the cylinder, said magnet valve on the inlet being adapted to suspend temporarily the operation of the timer, the magnet valve at the exhaust of the cylinder being controlled by the cancellation means.

4. A vigilance control device as claimed in claim 2 in which an auxiliary air chamber is connected to the main timing cylinder at the part of the stroke of the piston through a needle valve, the exhaust passage of the auxiliary chamber being fitted with a magent valve operating identically and in parallel with the magnet valve fitted to the exhaust passage of the main timing cylinder, arrangement being such that on simultaneous closing of the exhaust passages of timing cylinder and the auxiliary chamber, air entering through the inlet of the timing cylinder lifts the piston instantaneously and starts charging the auxiliary chamber until the pressure built up in the auxiliary chamber and at the bottom of the piston is such as to close the said second set of contacts thus giving an extended vigilance cycle.

5. A vigilance control device as claimed in claim 1 in which the power for the operation of the device is obtained from a battery and in one of the leads from the battery is fitted a multiple unit operation switch which remains closed when the vehicle is working as a single traction unit while it is opened to cut olf the battery supply when the vehicle is a trailing unit.

6. A vigilance control device as claimed in claim 5 in which an engine running switch is provided which is adapted to close on the starting of the engine to feed the power supply to the said device.

7. A vigilance control device as claimed in claim 5 in which a pressure switch is provided to temporarily suspend the working of the system when the vehicle is secured by application of brakes.

8. A vigilance control device as claimed in claim 1 in which there is provided an emergency cut-out switch to isolate the system in the event of its failure to respond to the normal controls of the said system.

9. A vigilance control device as claimed in claim 1 in which in addition to the concellation switch comprising a button, there are provided parallel switches installed in the throttle and whistle cock which can be operated by certain movements of the driver to signify his alertness.

References Cited UNITED STATES PATENTS 3,322,470 5/1967 Macdonald 303-49 FOREIGN PATENTS 856,052 12/ 1960 Great Britain. 856,053 12/ 1960 Great Britain.

OTHER REFERENCES German printed application No. 1,114,845, 10/1961, Kotulla.

DRAYTON HOFFMAN, Primary Examiner US. Cl. X.R. 303-19 

